JP3439965B2 - Liquid supply device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid supply device such as an ink supply device for supplying ink from an ink tank to a plate making section of a printing press. FIG. 3 is a diagram schematically illustrating an example of a conventional printing machine. This printing machine supplies ink stored in the ink tank 1 to the ink discharge unit 5 of the plate making unit 4 via the supply pipe 3 by the pump unit 2 and prints with the ink discharged from the ink discharge unit 5. Has become. As shown in FIG. 4, the pump unit 2 includes a motor 6, a trochoid pump 7, and a pump 7 that reduces the rotation of the motor 6.
And a reduction gear mechanism 8 that transmits the power to the transmission. The ink tank 1 has a cylindrical shape, and a piston 12 is slidably inserted into a tank body 11 having an ejection port 10 at one end thereof. The storage unit 13 is provided. Ink tank 1
The outlet 10 is detachably attached to a suction pipe 14 connected to the pump 7. When the pump 6 is operated by the motor 6, the ink B in the ink tank 1 is sucked into the pump 7 from the suction pipe 14, is further pressure-fed from the pump 7 to the feed pipe 3, and is supplied to the ink discharge unit 5. In the ink tank 1, the ink storage unit 13 becomes negative pressure as the ink B decreases, and accordingly, the pressure is pushed to the atmospheric pressure, and the piston 12 slides toward the discharge port 10 to secure the ink pressure feeding. Is done. When the ink B in the ink tank 1 runs out due to the operation, the ink tank 1 is detached from the suction pipe 14, and a new ink tank 1 filled with ink is set in the suction pipe 14. Since the pump 7 is disposed on the printing press side, the pump 7 needs a life equivalent to the number of ink tanks 1 to be replaced (for example, 300 hours or more in a row). Becomes Also, when sliding parts such as the gears or the casing of the pump 7 wear, the pump volume efficiency decreases and the discharge rate decreases, and the rotation time of the pump increases in order to obtain the same discharge rate as in the initial stage. The power consumption of the motor increases. Further, when replacing the ink tank 1, the suction port of the pump 7 is exposed to the outside.
At the time of replacement, foreign matter such as paper dust of a printed matter or a stapler needle may be mixed in, and the foreign matter may be caught and the pump 7 may be stopped. Some of these gear pumps are equipped with a filter to prevent foreign matter from entering.However, even in such a case, the filter becomes clogged due to long-term use and suction resistance increases, and the pump rotation time increases. And the power consumption of the motor increases. It should be noted that there is a piston type pump other than the above-mentioned gear type as a pump for feeding ink.
Although the piston type pump itself does not stop the pump due to foreign matter mixing as described above, the suction / discharge operation is performed by the check valve, so that the foreign matter bites into the seal surface of the check valve and the pump action is performed. The printing press may become unusable. Accordingly, it is an object of the present invention to provide a liquid supply device in which a discharge amount is not reduced due to abrasion of a sliding portion of a pump and a pump is not stopped due to foreign matter mixing. [0004] The present invention is a liquid supply apparatus for supplying liquid from a liquid tank to a supply target, wherein the liquid tank is cylindrical and has one end in the axial direction. A tank body provided with a discharge section detachably connected to a liquid supply section communicating with the supply section, and a pump driven section detachably connected to an external pump drive section; A piston that is slidably inserted in the axial direction of the tank body and that airtightly defines a liquid storage section between the one end of the tank body and the one end of the tank body. In the state in which the discharge section is connected to the liquid supply section, and the pump driven section is connected to the pump drive section, the pump driven section is operated by the pump driven section, whereby the liquid Liquid stored in storage And a pump for sucking the pressure and feeding the pressure to the discharge section is provided. According to the above configuration, the liquid tank is configured as a consumable. The discharge section of the liquid tank is connected to a liquid supply section that communicates with a supply section (for example, the discharge section of a plate making section in the case of the above-described printing press), and the pump driven section is connected to a pump drive section installed outside. Connect and set the liquid tank. When the pump drive section is operated, the pump operates via the pump driven section, the liquid stored in the liquid storage section in the tank is sucked into the pump, and the liquid is pumped from the discharge section to the liquid supply section. And supplied to the supplied part.
As the liquid in the tank decreases, the liquid storage section becomes negative pressure, and is pressed by the atmospheric pressure following the pressure, and the piston slides toward one end which is the discharge section side. When the liquid in the tank is exhausted due to the supply of the liquid, remove the discharge unit from the liquid supply unit and the pump driven unit from the pump drive unit, and remove a new liquid tank filled with liquid. Set to. [0006] The liquid tank has a built-in pump for pumping the liquid therein, and the distance between the pump and the liquid storage unit is inevitably very short, so that the suction resistance when the pump sucks the liquid is reduced. As a result, a decrease in the discharge amount is suppressed, and the pump can be downsized.
Or, because it is not necessary to increase the processing accuracy of the components of the pump because the liquid suction pressure is low,
Cost can be reduced. In addition, since the life of the pump is sufficient until all the liquid in the tank is completely discharged, the material of the components constituting the pump may be inexpensive,
From this, the cost can be reduced. In addition, the pump is built into the liquid tank,
Pump stoppage caused by foreign matter entering the pump when replacing the liquid tank is prevented. [0007] Further, according to a preferred embodiment of the present invention, in addition to the above-described configuration, the piston is provided at a portion of the piston facing the pump.
It is characterized in that a stopper is provided for forcibly stopping the operation of the pump when the piston is at the stroke end toward the pump. According to this configuration, when all the liquid in the tank has been discharged and a stroke end at which the piston does not further slide toward the pump is reached, the pump becomes inoperable by the stopper. For example, when the pump is of the trochoid type, the stopper is a convex portion that is engaged with a gear constituting the pump. In this case, when the piston reaches the stroke end, the gear of the pump bites the convex part, and the pump is forcibly stopped. This makes it possible to clearly determine that the remaining amount of the liquid is exhausted and the liquid tank needs to be replaced. It should be noted that it is time-consuming to make the pump reusable from this state, and combined with the fact that the configuration has become more complicated than before, an additional effect such as forgery prevention can also be obtained. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically illustrating a printing machine to which an ink supply device (liquid supply device) according to an embodiment indicated by reference numeral 20 is applied. This printing press
Ink is supplied from the ink supply device 20 to the ink discharge section (supplied section) 23 of the plate making section 22 via the supply pipe 21,
The printing is performed with the ink discharged from the ink discharge unit 23. The ink supply device 20 includes an ink tank (liquid tank) 24 and a trochoid pump 30 built in the ink tank 24. The ink tank 24 is, as shown in FIG.
A piston 26 is slidably inserted in the axial direction of the tank body 25 inside the cylindrical tank body 25. The piston 26 has an ink storage unit (liquid storage unit) between the piston body 26 and a bottom which is one end in the axial direction of the tank body 25.
25a is hermetically defined. A casing 27 is hermetically attached to the bottom of the tank body 25. The pump 30 is housed inside the casing 27 on the tank body 25 side, and an opening inside the casing 27 is covered with a cover 28. The pump 30 is operated by rotation of a pump shaft (pump driven portion) 31 that penetrates the casing 27 and protrudes to the outside. Reference numeral 40 in FIGS. 1 and 2 denotes a pump drive unit (pump drive unit) provided in the printing press. The pump drive unit 40 includes a motor 41 and a reduction gear mechanism 42 for reducing the rotation of the motor 41, and an output shaft 43 of the reduction gear mechanism 42 extends upward. The pump shaft 31 is detachably connected to the output shaft 43. Further, the pump drive unit 40 has an L-shaped joint pipe (liquid feeding section).
44 are provided. The feed pipe 21 is connected to one end of a side of the joint pipe 44 extending laterally. Further, a discharge pipe portion (discharge portion) 45 formed in the casing 27 is detachably connected to the other end on the side extending upward. That is, the ink tank 24 is detachably set to the printing press via the pump shaft 31 on the output shaft 43 of the pump drive unit 40 and via the discharge pipe 45 on the joint pipe 44, and can be replaced. Has become. The pump shaft 31 is connected to the output shaft 43 of the pump drive unit 40, and the discharge pipe 45 is connected to the joint pipe 44.
When the pump 30 is operated in a state where it is connected to the ink, the ink (liquid) B in the ink tank 24 is sucked into the casing 27 from the suction port 28 a formed in the cover 28, and is then pressure-fed to the discharge pipe 45, The ink is supplied to the ink discharge section 23 of the plate making section 22 through the joint pipe 44 and the feed pipe 21. With the supply of the ink, the amount of the ink B in the ink tank 24 decreases, and the ink storage section 25a becomes negative pressure, and the piston 26 slides toward the bottom of the tank body 25, that is, downwards. Move. When all the ink B in the ink tank 24 is discharged, at that time, the piston 26 comes to a stroke end in which the end surface (the surface facing the pump 30) 26a contacts the cover 28 and does not slide any more. On the end surface 26a of the piston 26 of the present embodiment, a projection (stopper) 29 which protrudes into the suction port 28a of the cover 28 at the end of the stroke and is engaged with the gear of the pump 30 is formed so as to protrude. The pump 30 is forcibly stopped by the gear of the pump 30 biting the projection 29. Next, the ink supply device 20 of the present embodiment
The operation of will be described. The ink tank 24 containing the pump 30 is a consumable item. The pump shaft 31 is connected to the output shaft 43 of the pump drive unit 40 by connecting a new ink tank 24 in which the ink storage unit 25a is filled with the ink B,
The discharge pipe section 45 is connected to the joint pipe 44 and set on the printing press. When the motor 41 rotates by the operation of the printing press, the power is transmitted from the reduction gear mechanism 42 to the pump shaft 31 via the output shaft 43, and the pump 30 operates. Pump 30
, The ink B in the ink tank 24 is sucked into the pump 30, is then pressure-fed to the discharge pipe section 45, and is further supplied from the joint pipe 44 to the ink discharge section 23 of the plate making section 22 via the feed pipe 21. . Then, the ink ejection unit 23
Printing is performed by discharging ink from the printer. As the amount of ink B in the ink tank 24 decreases, the pressure in the ink storage section 25a becomes negative, and the piston 26
Is pushed by the atmospheric pressure and slides toward the bottom of the tank body 25, that is, downward. Piston 2 due to lack of ink B
When the stroke end 6 is reached, the protrusion 2
9 enters the suction port 28a of the cover 28 and is caught by the gear of the pump 30, so that the pump 30 becomes inoperable. As described above, when the ink B in the ink tank 24 runs out due to the supply of the ink, the discharge pipe 45
And the pump shaft 31 is disconnected from the output shaft 43 of the pump drive unit 40 to remove the ink tank 24 from the printing press, and a new ink tank 24 filled with ink is similarly set. . According to the ink supply device 20 of the present embodiment, since the pump 30 incorporated in the ink tank 24 is in contact with the ink storage section 25a, the suction resistance when the pump 30 sucks the liquid is reduced. I do. As a result, a decrease in the discharge amount is suppressed, and the size of the pump 30 can be reduced. Alternatively, since the liquid suction pressure can be reduced, it is not necessary to increase the processing accuracy of the components of the pump 30. Also, the pump 30 controls the ink B in the ink tank 24.
The pump 30 may be made of inexpensive material such as resin instead of metal, as long as it has a life until all of the pump 30 is completely discharged. From these, cost can be reduced. Furthermore, since the pump 30 is built in the ink tank 24, foreign matter such as paper dust of printed matter and staples of a stapler is prevented from entering the pump 30 when the ink tank 24 is replaced. The stop of the pump 30 due to the above is prevented. Further, the gear of the pump 30 bites the convex portion 29 of the piston 26, and the pump 30 becomes inoperable.
4 can be clearly determined to be necessary. In order to make the pump 30 reusable from this state, a considerable amount of time is required. In addition, since the configuration is more complicated than before, an additional effect such as forgery prevention can be obtained. The present invention is not limited to the above-described embodiment. For example, the pump incorporated in the ink tank 24 may be a trochoid type pump, a piston type pump, an impeller type pump or the like. A form of pump can be used. Further, the convex portion 29 is employed as the stopper, but the stopper may be of any form as long as it has a function of forcibly stopping the pump at the end of the stroke of the piston. Further, the above-described embodiment is an example in which the present invention is applied to an ink supply device of a printing press, and the present invention is not limited to this. It can be applied to various liquid supply devices. As described above, according to the present invention, the pump is built in the consumable liquid tank, and the distance between the pump in the liquid tank and the liquid storage becomes extremely short. Since the suction resistance of the pump when sucking liquid is reduced, a decrease in the discharge amount is suppressed, and the pump can be downsized, or the components of the pump can be processed because the liquid suction pressure is low. There is no need to increase accuracy. In addition, the service life of the pump may be sufficient until all the liquid in the tank is completely discharged, so that the material of the components constituting the pump may be inexpensive. From these, cost can be reduced. Further, since the pump is built in the liquid tank, it is possible to prevent the pump from being stopped due to foreign matter entering the pump when the liquid tank is replaced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a printing machine to which an ink supply device according to an embodiment of the present invention has been applied. FIG. 2 is a partial cross-sectional side view of an ink supply device according to an embodiment of the present invention. FIG. 3 is a schematic diagram of a printing press provided with a conventional ink supply device. FIG. 4 is a partial cross-sectional side view of a conventional ink supply device. [Description of Signs] 20 Ink supply device (liquid supply device) 23 Ink ejection portion (supplied portion) 24 Ink tank (liquid tank) 25 Tank main body 25a Ink storage portion (liquid storage portion) 26 Piston 29 Convex portion (stopper) Reference Signs List 30 pump 31 pump shaft (pump driven section) 40 pump drive unit (pump drive section) 44 joint pipe (liquid feeding section) 45 discharge pipe section (discharge section) B ink (liquid)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B41F 31/08 B41L 13/18 B65D 83/00 G03G 15/11

Claims (1)

(1) A liquid supply device for supplying a liquid from a liquid tank to a supply target, wherein the liquid tank is cylindrical and has one end in an axial direction thereof. A tank body provided with a discharge section detachably connected to a liquid supply section communicating with the supply section, and a pump driven section detachably connected to an external pump drive section, and inside the tank body, A piston that is slidably inserted in the axial direction of the tank body and that airtightly defines a liquid storage section between the one end of the tank body and the one end of the tank body. The pump storage unit is operated by the pump drive unit in a state where the discharge unit is connected to the liquid supply unit and the pump drive unit is connected to the pump drive unit. Inhaling the liquid stored in the Pump that pumps are provided in the output portion, opposite of the pump in the said piston
At the stroke end of the piston toward the pump
With a stopper to forcibly stop the operation of the pump
Liquid supply apparatus characterized by there.